* Replace WIN32 conditions with _WIN32 or PHP_WIN32
WIN32 is defined by the SDK and not defined all the time on Windows by
compilers or the environment. _WIN32 is defined as 1 when the
compilation target is 32-bit ARM, 64-bit ARM, x86, or x64. Otherwise,
undefined.
This syncs these usages one step further.
Upstream libgd has replaced WIN32 with _WIN32 via
c60d9fe577
PHP_WIN32 is added to ext/sockets/sockets.stub.php as done in other
*.stub.php files at this point.
* Use PHP_WIN32 in ext/random
* Use PHP_WIN32 in ext/sockets
* Use _WIN32 in xxhash.h as done upstream
See https://github.com/Cyan4973/xxHash/pull/931
* Update end comment with PHP_WIN32